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solid of 1-phenylurea18a (250 mg, 94%); 1H NMR (300 MHz, d 9.91 (s, 1H, NH), 7.99 (s, 1H), 7.84–7.81 (m, 1H), 6.8–6.7 (m,
DMSO-d6): d 5.81 (s, 2H, NH), 6.88 (t, J ¼ 15 Hz, 1H), 7.21 (t, J ¼ 3H), 6.19 (s, 2H, NH).
15 Hz, 2H), 7.38 (d, J ¼ 6 Hz, 2H), 8.49 (s, 2H).
Entry 12; 1-(3-hydroxyphenyl)urea. The product was isolated
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The compounds from Table 2 (entries 2–16, 19, 20, 36, 39, 40) as pale yellow solid (203 mg, 67%); H NMR (300 MHz, DMSO-
were synthesized based on this method. The analytical data of d6): d 9.22 (s, 1H, NH), 8.4 (s, 1H), 7.0–6.9 (m, 2H), 6.71–6.7 (m,
these compounds is mentioned below:
1H), 6.34–6.30 (m, 1H), 5.79 (s, 2H, NH). 13C-NMR (300 MHz,
Entry 2; 1-(4-chlorophenylphenyl)urea.18a The product was DMSO-d6): d 158.09, 156.36, 142.05, 129.67, 108.70, 105.27. APCI
isolated as white solid (308 mg, 90%); 1H NMR (300 MHz, MS: (M + 1)153, 148.9, 134, 121, 110.
DMSO-d6): d 8.66 (s, 1H), 7.43–7.39 (m, 2H), 7.27–7.23 (m, 2H),
5.89 (s, 2H, NH).
Entry 13; 1-(4-hydroxyphenyl)urea.24 The product was iso-
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lated as white solid (270 mg, 89%); H NMR (300 MHz, DMSO-
Entry 3; 1-(3,4 dichlorophenyl)urea. The product was iso- d6): d 8.94 (s, 1H), 8.51 (s, 1H, NH), 7.15 (d, J ¼ 9 Hz, 2H), 6.63 (d,
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lated as white solid (290 mg, 71%); H NMR (300 MHz, DMSO- J ¼ 9 Hz, 2H), 5.64 (s, 2H, NH).
d6): d 8.75 (s, 1H, NH), 7.80–7.77 (m, 1H), 7.21–7.24 (m, 2H), 5.96
Entry 14; 4-ureidobenzoic acid.25 The product was isolated as
(s, 2H, NH). 13C-NMR (300 MHz, DMSO-d6): d 156.19, 141.28, white solid (yield: 300 mg, 83%); 1H NMR (300 MHz, DMSO-d6):
131.31, 130.28, 122.66, 119.12, 118.19. APCI MS: (M, M + 2), d 9.14 (s, 1H, NH), 7.72 (d, J ¼ 6 Hz, 2H), 7.29 (d, J ¼ 6 Hz, 2H),
204.9, 207.0, 163.9, 161.9, 129, 127.
6.02 (m, 3H), 6.19 (s, 2H, NH), 5.50 (s, 1H).
Entry 4; 1-(2-bromophenyl)urea. The product was isolated as
Entry 15; 1-(4-cyanophenyl)urea. The product was isolated as
white solid (400 mg, 93%); 1H NMR (300 MHz, DMSO-d6): white solid (150 mg, 47%); 1H NMR (300 MHz, DMSO-d6): d 9.02
d 8.02–8.06 (m, 1H), 7.85 (s, 1H, NH), 7.52 (d, J ¼ 6 Hz, 1H), 7.27 (s, 1H, NH), 7.73–7.61 (m, 2H), 7.58–7.55 (m, 2H), 6.11 (s, 2H,
(t, J ¼ 18 Hz, 1H), 6.90 (m, 1H), 6.42 (s, 2H, NH). 13C-NMR (300 NH). 13C-NMR (300 MHz, DMSO-d6): d 155, 145, 133, 119, 117,
MHz, DMSO-d6): d 156.04, 138.32, 132.75, 128.34, 123.75, 102. APCI MS: (M + 1) 162.0, 142, 119.1.
122.41, 112.87. APCI MS: 214.9 (M+), 216.9 (M + 2), 173.9, 171.9,
170.9, 169.9.
Entry 16; 4-methoxyphenyl urea.26 The product was isolated
as brown solid (234 mg, 70%); H NMR (300 MHz, DMSO-d6):
Entry 5; 1-(3-bromophenyl)urea.18a The product was isolated d 8.29 (s, 1H, NH), 7.26–7.29 (m, 2H), 6.78–6.81 (m, 2H), 5.70 (s,
as white solid (352 mg, 82%); 1H NMR (300 MHz, DMSO-d6): 2H, NH), 3.68 (s, 3H).
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d 8.76(S, 1H, NH), 7.85 (t, J ¼ 3 Hz, 1H), 7.22–7.26 (m, 1H), 7.18
Entry 19; 2-(4-ureidophenyl)acetic acid. The product was
isolated as off white solid (315 mg, 81%); H NMR (300 MHz,
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(d, J ¼ 6 Hz, 1H), 7.07–7.11 (m, 1H), 5.98 (s, 2H, NH).
Entry 6; 1-(4-bromophenyl)urea.22 The product was isolated DMSO-d6), d 8.99 (s, 1H, NH), 7.33 (d, J ¼ 9 Hz, 2H), 7.08 (d, J ¼
as light brown solid (344 mg, 80%); 1H NMR (300 MHz, CD3OD): 6 Hz, 2H), 5.97 (s, 2H, NH), 5.50 (s, 1H, NH), 3.38 (s, 2H, NH).
d 7.38 (d, J ¼ 9 Hz, 2H), 7.34 (d, J ¼ 9 Hz, 2H).
Entry 7; 1-(3-triuoromethoxyphenyl)urea. The product was 127.97, 118.14. APCI MS: (M + 1) 195.1, 178.0.
isolated as white solid (350 mg, 80%); 1H NMR (300 MHz,
Entry 20; 4-(ureidomethyl)benzoic acid. The product was
13C-NMR (300 MHz, DMSO-d6): d 173.46, 156.50, 139.55, 130.30,
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DMSO-d6): d 8.87 (s, 1H, NH), 7.94 (s, 1H), 7.50–7.39 (m, 2H), isolated as off white solid (285 mg, 73%); H NMR (300 MHz,
7.19 (d J ¼ 9 Hz, 1H), 5.98 (s, 2H, NH). 13C-NMR (300 MHz, DMSO-d6): d 7.91 (d, J ¼ 6 Hz, 2H), 7.34 (d, J ¼ 9 Hz, 2H), 6.57 (t, J
DMSO-d6): d 156.23, 149.16, 142.84, 130.61, 116.68, 113.29, ¼ 12 Hz, NH), 5.67 (s, 2H, NH), 4.25 (d, J ¼ 6 Hz, 2H). 13C-NMR
110.11. APCI MS: (M + 1) 221.0, 204, 178, 135, 122, 107.
(300 MHz, D2O): d 159.40, 129.79, 126.99, 42.97. APCI MS: (M +
Entry 8; 1-(3-triuoromethylphenyl)urea. The product was 1) 194.9, 153, 135, 107.
isolated as white solid (256 mg, 63%); 1H NMR (300 MHz, Entry 36; N-carbamoyl-phenylalanine.32 The product was
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DMSO-d6): d 8.83 (s, 1H, NH), 7.63 (s, 1H), 7.31 (t, J ¼ 15 Hz, 1H), isolated as off white solid (260 mg, 63%); H NMR (300 MHz,
7.20 (d, J ¼ 6 Hz, 1H), 6.44 (d, J ¼ 6 Hz, 1H), 5.96 (s, 2H, NH). DMSO-d6) d 7.31–7.17 (m, 5H), 6.13 (d, J ¼ 6 Hz, 1H), 5.60 (s, 2H,
13C-NMR (300 MHz, DMSO-d6): d 156.32, 141.87, 122.94, 121.64, NH), 4.43–4.28 (m, 1H), 3.02–2.85 (m, 1H), 2.83–2.49 (m, 1H).
117.72, 114.05. APCI MS: (M + 1) 205.0, 162, 142, 93.
Entry 39; 1-(1H benzo[d]-imidazol-2-yl)urea. The product was
Entry 9; 1-(3, 5-dimethylphenyl)urea. The product was iso- isolated as yellow solid (248 mg, 70%); 1H NMR (300 MHz,
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lated as white solid (320 mg, 97%); H NMR (300 MHz, DMSO- DMSO-d6): d 7.11–7.14 (m, 2H), 6.87–6.90 (m, 2H), 6.26 (s, 2H,
d6): d 8.32 (s, 1H, NH), 7.00 (s, 2H), 6.53 (s, 2H), 5.77 (s, 2H, NH), NH), 5.43 (s, 1H, NH). 13C-NMR (300 MHz, DMSO-d6); d 155,
2.19 (s, 6H). 13C-NMR (300 MHz, DMSO-d6): d 156.43, 140.84, 138.27, 119.84, 111.94, 21.86. APCI MS: 159.9, 134.0, 92.1.
137.91, 123.15, 115.92, 21.61. APCI MS: (M + 1) 165.1, 148, 133.1,
122.1.
Entry 40; 1-(H-pyrazol-3-yl)-urea. The product was isolated as off
white solid (177 mg, 70%). H NMR (300 MHz, DMSO-d6 + D2O),
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Entry 10; 1-(4-isopropylphenyl)urea. The product was iso- d 8.08 (d, J ¼ 2.7 Hz, 1H), 6.27 (s, 1H), 6.26 (s, 2H, NH), 5.43 (s, 1H,
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lated as white solid (316 mg, 88%); H NMR (300 MHz, DMSO- NH). 13C-NMR (300 MHz, DMSO-d6): d 155, 138.27, 119.84, 111.94,
d6): d 8.40 (s, 1H, NH), 7.30 (d, J ¼ 9 Hz, 2H), 7.09 (d, J ¼ 9 Hz, 21.86. APCI MS: 159.9, 134.0, 92.1, 127 (M + 1), 110.1, 82.
2H), 5.77 (s, 2H, NH), 2.84–2.79 (m, 1H), 1.18 (d, J ¼ 6 Hz, 6H).
13C-NMR (300 MHz, DMSO-d6): d 156.53, 141.51, 138.71, 126.73,
118.40. APCI MS: (M + 1) 179.2, 162, 137.1, 120.1.
Procedures for synthesis of N-benzyl urea (2b) from benzylamine (2a)
Entry 11; 1-(2-hydroxyphenyl)urea.2 The product was isolated To a stirring solution of benzylamine (1b, 2 mmol), and 1 N
as white solid (275 mg, 90%); 1H NMR (300 MHz, DMSO-d6): aqueous HCl (3 mL), potassium cyanate (4.4 mmol; 2.2 equiv.)
was added. The reaction mixture was allowed to stir at room
21592 | RSC Adv., 2018, 8, 21585–21595
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